Merge pull request #966 from MikeMcQuaid/keg-lock-constants

Library/Homebrew/cmd/list.rb

Library/Homebrew/diagnostic.rb

Library/Homebrew/extend/ARGV.rb

Library/Homebrew/formula.rb

Library/Homebrew/formula_lock.rb

Library/Homebrew/formula_pin.rb

Library/Homebrew/global.rb

Library/Homebrew/keg.rb

Library/Homebrew/migrator.rb

Library/Homebrew/test/test_formula.rb

Library/Homebrew/test/test_formula_installer.rb

Library/Homebrew/test/test_formula_lock.rb

Library/Homebrew/test/test_formula_pin.rb

Library/Homebrew/test/test_integration_cmds.rb

Library/Homebrew/test/test_migrator.rb